1. Field of the Invention
This invention relates to industrial and commercial guide bushings for use in a wide variety of applications.
There is a continuing need for a lightweight, low-cost, self-lubricating guide bushing for use in industrial and commercial applications. Bushings having a self-lubricating bearing sleeve made from a fabric reinforced thermoset composite could be of substantial use if there were a low-cost simple way of assembling such fabric reinforced thermoset composite within a bushing shell.
2. Background Art
U.S. patents showing bushings over which my disclosure represents an improvement are as follows:
U.S. Pat. No. 5,685,057
U.S. Pat. No. 3,945,695
U.S. Pat. No. 4,740,117
A publication entitled xe2x80x9cGeneral Engineering Manualxe2x80x9d by Orkot Ltd. of Bradmarsh Business Park, Rotherham, S60 1 BX, South Yorkshire, England, also shows prior art information.
I have discovered that a fabric reinforced thermoset composite sleeve may be incorporated within an outer shell of a bushing in a construction which enables the sleeve to be press-fitted within the shell to be held therein by a constriction in the shell bore which is embraced by the bearing liner. As the inner bearing sleeve or liner is pressed axially into the shell, it encounters the constriction which is shaped to permit the sleeve to be squeezed past it. Because the sleeve is distorted at the constriction, the sleeve bore is reamed or otherwise sized after installation of the sleeve to provide a uniform internal diameter throughout the sleeve. The constriction of the shell is greater than the running clearance between the inside diameter of the sleeve and the outside diameter of the shaft or pin carried by the bushing, such that the sleeve cannot work its way out of the bushing once the shaft is in place during operation thereof.